New York (AFP)

The United States plans to proceed in "a few weeks" to the certification flight of the Boeing 737 MAX, a decisive step for the return to service of this plane grounded for almost a year, despite a new problem detected recently.

On a trip to London, Steve Dickson, head of the Federal Aviation Agency (FAA), the main airline regulator in the United States, told reporters at the Aviation Club that the flight 737 MAX certification takes place in "a few weeks".

It is traditionally at the end of the certification flight that the civil aviation authorities decide whether or not to authorize an aircraft to enter or resume service.

In the case of the 737 MAX, it would mark the beginning of the end of a historic crisis, the bill of which amounts for the moment to more than 18 billion dollars for Boeing, without counting the efforts which it will have to deploy to restore its reputation and the potential compensation of the families of the victims.

The FAA completed "several weeks ago" its audit of changes made by Boeing to the MCAS anti-stall software, implicated in the accidents of Lion Air on October 29, 2018 (189 dead) and Ethiopian Airlines on 10 March 2019 (157 dead), a regulatory source told AFP.

She concluded that adjustments would be necessary, but these would not be a priori "significant", said the same source.

- Alarm malfunction -

At the same time, Boeing engineers detected a new concern related to MCAS, software supposed to prevent the plane from dive, especially in case of loss of speed.

The discovery took place during a test flight intended to test the MCAS, explains Boeing: the flashing light, supposed to light up only in the event of a malfunction of this software, lit unexpectedly, a problem due, according to Boeing, to the differences in the data entered into flight control computers.

This annoyance does not affect the return to service schedule of the plane, assured Boeing in an email to AFP. Mid-January the giant of Seattle (northwest) announced that the MAX could a priori fly in mid-2020, a deadline considered realistic by American Airlines, United Airlines and Southwest, which postponed the flights scheduled on this plane to summer.

"We are in the process of changing the software (...) to ensure that the flashing light only lights up when it is necessary," Boeing said on Thursday.

The aircraft manufacturer, whose new managing director, David Calhoun, has promised more transparency after ten months of crisis management deemed calamitous by its predecessor, said it had informed regulators of the malfunction in the week of January 20. Customer airlines have also been notified.

The news was causing Wall Street action to jump almost 4%, with markets looking relieved to see that the epilogue of MAX's setbacks is imminent.

However, Boeing still has work to do before getting the green light from the regulators. He must propose a solution to solve a problem related to the electrical wiring of the aircraft.

According to an internal source, it is still premature to think that it will require a new design, an extreme option because it could delay the return to service of the MAX.

Another additional pitfall to overcome: Boeing must provide documentation related to pilot training, but it is up to the FAA to decide what will be the best way to train them. We are moving towards more expensive simulator training.

© 2020 AFP